graphics/Coin: unbreak fetch

A fork can be renamed or deleted, so get PR commits via upstream.

fetch: https://github.com/unrelentingtech/coin/commit/3053d28b74d.patch: Not Found
fetch: https://github.com/coin3d/coin/commit/3053d28b74d.patch: size mismatch: expected 1408, actual 1410

-index 6c039a0a3..007461cbd 100644
+index 6c039a0a36..007461cbd4 100644